/*
 * HttpAuth
 *
 * Copyright (C) 2004 Stefan Walter
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU General Public License for more details.
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the
 * Free Software Foundation, Inc.,
 * 59 Temple Place, Suite 330,
 * Boston, MA 02111-1307, USA.
 */

#ifndef __HTTPAUTHD_H__
#define __HTTPAUTHD_H__

#include "buffer.h"
#include <syslog.h>

/* -----------------------------------------------------------------------
 * HTTP Auth Handlers
 */

struct ha_context;
struct ha_request;

/*
 * This function initializes the handler. It gets called
 * after the configuration gets loaded so if a config func
 * is registered it'll get called before this.
 */
typedef int (*auth_init_t)(struct ha_context* ctx);

/*
 * This function is called when the app exits. All threads
 * should have completed at this point, so it's not necessary
 * to be thread safe in here
 */
typedef void (*auth_destroy_t)(struct ha_context* ctx);

/*
 * Called once for each configuration parameter. This is
 * called before the initialization function. 'name' will
 * always be lower case. White space will always be trimmed
 * from the value.
 */
typedef int (*auth_config_t)(struct ha_context* ctx, const char* name, const char* value);

/*
 * Called for each authentication request that is designated
 * for this handler. Note that all data access in this
 * function must be thread-safe.
 */
typedef int (*auth_process_t)(struct ha_request* rq);

/* An authentication handler */
typedef struct ha_handler
{
    const char* type;
    auth_init_t f_init;           /* #1 Called to initialize handler */
    auth_destroy_t f_destroy;     /* #3 Called when exiting */
    auth_config_t f_config;       /* #0 Called for each config param */
    auth_process_t f_process;     /* #2 Called for each auth request */
    const void* context_default;  /* The default context */
    const size_t context_size;    /* Bytes of extra context needed */
}
ha_handler_t;

/*
 * OK signifies that things went according to plan.
 */
#define HA_OK     0

/*
 * FALSE: the process failed but it wasn't an error.
 */
#define HA_FALSE  1

/*
 * ERROR means a bad error happened which will kill the
 * current processing thread. Examples are out of memory
 * errors or the like.
 */
#define HA_CRITERROR  -1

/*
 * FAILED: something internal to the server failed.
 */
#define HA_FAILED -2

/*
 * BADREQ means that we got a bad request or call.
 */
#define HA_BADREQ -3


/* Context passed to the handler functions above */
typedef struct ha_context
{
    const char* name;                   /* A name assigned by the configuration file */
    const ha_handler_t* handler;        /* The original handler structure */
    void* ctx_data;                     /* Handler specific data */

    /* Context specific options */
    unsigned int allowed_types;
    int cache_timeout;
    int cache_max;

    /* For basic and digest auth: */
    const char* realm;

    /* For digest auth: */
    unsigned int digest_ignoreuri : 1;
    unsigned int digest_ignorenc : 1;
    const char* digest_debugnonce;
}
ha_context_t;


/* -----------------------------------------------------------------------
 * HTTP Auth Structures and Constants
 */

/*
 * The maximum number of commands in any httpauth
 * command. This is defined by the protocol. There
 * should be no need to change it unless we're
 * adding or removing commands
 */
#define HA_MAX_ARGS        4

/*
 * The maximum number of pertinent headers to read
 * from the client. If you need to add valid headers
 * make sure to update this number *and* the list
 * of valid headers in httpauthd.c
 */

#define HA_MAX_HEADERS     2

/*
 * The maximum number of handlers. If you add
 * handlers make sure to update this number.
 */
#define HA_MAX_HANDLERS    4


/* A single header in memory */
typedef struct ha_header
{
    const char* name;
    const char* data;
}
ha_header_t;

/* The various command codes */
#define REQTYPE_IGNORE  0
#define REQTYPE_QUIT    1
#define REQTYPE_AUTH    2
#define REQTYPE_SET     3

#define AUTH_ARG_CONN   0
#define AUTH_ARG_METHOD 1
#define AUTH_ARG_URI    2

/* A single request from client along with response */
typedef struct ha_request
{
    unsigned int id;                            /* Unique connection identifier */

    int req_type;                               /* The command type */
    const char* req_args[HA_MAX_ARGS];          /* Arguments for the command */
    ha_header_t req_headers[HA_MAX_HEADERS];    /* Headers for command */

    /* Additional request info */
    ha_context_t* context;
    const char* digest_domain;

    /* The buffer in use for the request */
    ha_buffer_t* buf;

    /* The buffer in use for the connection */
    ha_buffer_t* conn_buf;

    int resp_code;                              /* The response code */
    const char* resp_detail;                    /* The details for response */
    ha_header_t resp_headers[HA_MAX_HEADERS];   /* Headers for the response */
}
ha_request_t;

/* The various response codes for the client */
#define HA_SERVER_READY    100
#define HA_SERVER_OK       200
#define HA_SERVER_ACCEPTED 202
#define HA_SERVER_DECLINE  401
#define HA_SERVER_BADREQ   400
#define HA_SERVER_BUSY     500

/* Request functions */
const ha_header_t* ha_findheader(const ha_request_t* rq, const char* name);
const char* ha_getheader(const ha_request_t* rq, const char* name, const char* prefix);

/* Response functions */
void ha_addheader(ha_request_t* rq, const char* name, const char* data);

/* Configuration functions */
int ha_confbool(const char* name, const char* conf, int* value);
int ha_confint(const char* name, const char* conf, int min, int max, int* value);

/* -----------------------------------------------------------------------
 * Error Handling
 */

void ha_message(const ha_request_t* rq, int level, const char* msg, ...);
void ha_messagex(const ha_request_t* rq, int level, const char* msg, ...);
void ha_memerr(const ha_request_t* rq);


/* -----------------------------------------------------------------------
 * Authentication types
 */


/* The various types of authentication */
#define HA_TYPE_BASIC   1 << 1
#define HA_PREFIX_BASIC "Basic "

#define HA_TYPE_DIGEST  1 << 2
#define HA_PREFIX_DIGEST "Digest "

#define HA_TYPE_NTLM    1 << 3
#define HA_PREFIX_NTLM  "NTLM "

/* -----------------------------------------------------------------------
 * URI Parse Support
 */

typedef struct ha_uri
{
    const char* scheme;
    const char* user;
    const char* pw;
    const char* host;
    unsigned short port;
    const char* path;
    const char* query;
    const char* fragment;
}
ha_uri_t;

char* ha_uriformat(ha_buffer_t* buf, const ha_uri_t* uri);
int ha_uriparse(ha_buffer_t* buf, const char* suri, ha_uri_t* uri);
int ha_uricmp(ha_uri_t* one, ha_uri_t* two);


/* -----------------------------------------------------------------------
 * Locking
 */

void ha_lock();
void ha_unlock();


/* -----------------------------------------------------------------------
 * Miscellaneous
 */

int ha_genrandom(unsigned char* data, size_t len);


#endif /* __HTTPAUTHD_H__ */